MA35D1 Adjust Volume Noise Problem
Answer.
Turn on the NAU88L24 DAC Zero Crossing function.
See nau8824 registers below: .
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Use amixer to enable the Headphone Zero Crossing function of the audio codec.
The command:
Code: Select all
$ amixer cset numid=xx 1
**numid can use the amixer control command to search for 'Headphone ZC Switch' to get the corresponding number id.
For example:
Code: Select all
$ amixer controls
numid=28,iface=MIXER,name='Headphone ZC Switch'
numid=30,iface=MIXER,name='Headphone Volume'
numid=29,iface=MIXER,name='Headphone Playback Switch'
numid=6,iface=MIXER,name='PCM Volume'
numid=37,iface=MIXER,name='Aux Boost Volume'
numid=39,iface=MIXER,name='ADC 128x Oversampling Switch'
numid=1,iface=MIXER,name='ADC Companding'
Code: Select all
$ amixer cset numid=28 1
numid=28,iface=MIXER,name='Headphone ZC Switch'
; type=BOOLEAN,access=rw------,values=2
: values=on,on
#
For example, the current volume is 1, and if you want to adjust it to 10, you need to gradually increase it from 1, 2, 3, 4... to 10.
Whether you want to change the codec or the SOC, you need gradients.
#MA35 , #DDR #buildroot #ma35d16ab1a
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